The list in the abstract

> Additionally, all these environmental factors such as X-rays, gamma rays, the radiation emitted from radioactive materials, aniline type dyes, cigarette, free radicals, asbestos, silica dust, air pollution, food additives, various drugs, some of the chemicals used in perfumes, oncogenic viruses and bacteria are playing an important role in cancer formation and contribute the increase of incidence of cancer.

Do the four you cited really cover 50% ?

E.g. moving to a place with less air pollution or better building materials could have a lot more effect than fixing your diet if you're in the average.